Bartolomeo Cristofori is one of the greatest names in the field of
keyboard instrument making of all time. The design and the skill of execution
of his piano escapement action were not really superseded from its invention in
about 1700 until Erard patented his double escapement mechanism in 1821.
Many of his ideas such as the inverted wrestplank can still be found in pianos
dating from a period 150 years after Cristofori's death, and indeed many of the principles of his action are still to be found
in the modern grand piano of the present day.

Although
Cristofori’s name is well-known as the first to design a successful and
efficient piano action and his harpsichords, cembali
traversi, spinettoni, and spinette ovale are beautifully
designed and exhibit an ingenuity and inventiveness found in no other maker of
the historical period. They are also executed with a hand capable of
workmanship of unsurpassed quality, and this extends to Cristofori’s pupil
Giovanni Ferrini. But his skills as a harpsichord builder and as a
restorer of old, earlier instrument in order to bring them up to date with
contemporary instruments are less well recognised. The re-working of earlier
instruments which Cristofori and Ferrini altered in order to give them a
compass, disposition and pitch useful for the contemporary musical environment
which existed in Florence at the beginning of the eighteenth century.

In this paper
I want to discuss this latter aspect of Cristofori and Ferrini’s creative
output. I want to show that Cristofori, or perhaps his pupil Giovanni
Ferrini, had a hand in the alteration of two unsigned and undated harpsichords
in British collections. One of these instruments is in the Donaldson
Collection of the
Royal College of Music in London and bears the
catalogue number 175; the other is in the
Russell Collection of Early Keyboard
Instruments at the University of Edinburgh in Scotland. I want to show first of
all that both of these instruments were made in the southern part of Italy, and
I then want to demonstrate that Cristofori or Ferrini had a hand in the
alteration of these instruments. Along the way there are some interesting
developments and discoveries.

The use of simple geometry in the construction
of Italian keyboard instruments

The work that I have done recently in this
field and illustrated below shows that the maker began his design by drawing out
the baseboard using dimensions which were simple integers or fractions of the
local unit of measurement, and the case sides that he then applied to the sides
of the baseboard in the workshop were cut to a height also equal to a simple
number of units, or units plus simple fractions. The combination of the fact
that the case sides were hand thicknessed and therefore not all of exactly the
same thickness (not even from one end of the board to the other) and the
irregular geometry of both polygonal virginals and harpsichords, meant that the
resulting final outside dimensions of the instrument were totally unrelated to
the local unit of measurement used by the maker. Therefore a maker starting
with two identically-dimensioned baseboards constructed according to his design
could end up with slightly differently-sized cases after the sides were added to
the two identical baseboards. Similarly it is the height of the case without
the top cap moulding that the maker would measure in his local unit of
measurement[1].
He would mark out a number of planks all of the same width in convenient units
and then cut and apply these to the outside edges of the baseboard. Experience
measuring Italian instruments has shown that even here, the case-wall heights
are often slightly less than expected in places where the top of the case has
been planed down to equalise the level of the top of the case at the corners
when these did not match exactly after the case sides were assembled. It is
therefore the maximum case-wall height that corresponds to the makers
design and not the average case-wall height. Similarly the position of the
soundboard was located by choosing a simple distance from the top of the
soundboard liner relative to the top or the bottom of the case boards and this
would have been marked out with a marking gauge before the case sides were
assembled and attached to the baseboard. The bottom of the soundboard was
therefore not positioned relative to the upper surface of the baseboard, and
similarly the top of the soundboard (which was usually made to have a variable
thickness for acoustical reasons) was similarly also unrelated in simple units
of the local measurement to the position of the top or bottom of the case.

The problem faced by an investigator is to find the unit of
measurement used to design and construct any given instrument. A harpsichord or
a polygonal virginal has many different measurements and it is not at all
obvious from looking at the millimetre measurements what the local unit used to
arrive at them was. This is further complicated by the fact that, being hand
made, none of the measurements is perfectly exact. Any method used to find the
unit of measurement must therefore also be relatively independent of any
inaccuracies resulting from the working methods of the maker.

I want to show here,
first of all, how some of the basic principles used by Italian makers when
setting out their design for the baseboards of both polygonal virginals and
harpsichords were based on the local unit of measurement. The method used by
these makers is based on the way in which they used a simple geometrical
construction to arrive at the corner angles of polygonal virginals and the tail
angle of harpsichords. Working in reverse, a study of the measurement of the
angles and sides of these corners enables a calculation of the unit of
measurement. Establishing the unit of measurement used in the design of the
instrument can then be used to determine the centre in which it was built[2].
The importance of such a method to the determination of the maker of an
anonymous instrument is clear. The method clearly does not pinpoint precisely
who the maker was, but it does reduce the number of possible makers from the
vast breadth of Italian harpsichord, virginal and spinet builders. It suffices
then to compare the anonymous instrument in question with other similar
instruments by known builders from the same city or region.

I would like to illustrate
the method that I have developed to arrive at the unit of measurement for a
harpsichord which uses a very simple geometry, and then apply the method to the
two harpsichords under study here. Having established the unit of measurement
used in the construction of these two harpsichords I then want to show that the
alterations to these two instruments were executed using the Florentine inch or
soldo.

Unfortunately the usual catalogue measurements of Italian
harpsichords and virginals do not normally enable one to make an analysis of the
size of the baseboard from which the maker began the design and construction of
the instrument. It is therefore necessary to measure the baseboard (if possible
by removing the keyboard and jacks and inverting the instrument) without the
case sides and then to analyse these measurements.

Figure 1 -
¾-view in its original case and with its original Neapolitan stand

Anonymous Italian single-manual
harpsichord, Naples, c.1620

Russell Collection, Edinburgh, Cat.
No. HS1-A1620.2

The
measurements of the baseboard and case show clearly that this instrument was
made in Naples (click
here for further details). The anonymous harpsichord in the
Russell Collection (Figure 1), although it has a few minor features in common
with the 'Neapolitan
School of Stringed Keyboard Instrument Making', is clearly built in a
quite different style. The only similarity with the ‘Neapolitan’ school is
the panelled front of the nameboard. Otherwise the case sides are of
cypress and not of maple, and they do not project down below the lower surface
of the baseboard. The keyboard does not, and never did, slide in and out
of the instrument like a drawer, and the tail has a blunt angle and is not
pointed like the harpsichords built in this so-called ‘Neapolitan’ tradition.

The anonymous harpsichord in the
Royal College
of Music, London, No. 175

This is a
fine example of an instrument built in the Neapolitan tradition (Figure 2) (Click
here to go to a list of the characteristics of the keyboard instruments built in
the Neapolitan school). It has case sides of maple, a wide lower
outside case moulding, and the case sides project slightly below the level of
the bottom of the baseboard. The panelled nameboard, the jackrail mounting
system, the keyboard that slides in and out of the case like a drawer, the
pointed tail angle, etc. are also all characteristics ascribed to this
‘Neapolitan’ school.

The tail angle of this instrument was
measured to be 36½º, and the tangent of this angle is tan 36½º = 0.74 is close
to
0.7356 = suggesting that the sides of the triangle making up the tail
angle have lengths of 10once and 14½ once. Using these to estimate the
size of the oncia being used here, the lengths in once of the
other measurements of the baseboard and case height can be made. These are
shown in Table 1.

A look at a
table of the units of measurement used in the various centres in
Italy during the historical period shows that in Naples the palmo,
divided into 12 units, had a length of 262.01mm[3].
Hence the oncia had a length of:

mm

This value
is close to the value of length of the oncia found above but is
significantly different from it. However, many of the features of this
instrument are clearly typical of Neapolitan practice, and many are
characteristic of Onofrio Guarracino. But if this ‘textbook’ value were
actually the length of the oncia being used by Guarracino the length of
the spine side of the baseboard would have been 21.834x84
= 1834mm an easily-measurable 17mm difference from the 1817 mm found here.
However, the values of the oncia determined by me from some other
instruments by Guarracino are given in the table below:

Table 2 - The unit of measurement used in various
instruments by Onofrio Guarracino, Naples, active in the second half of the
seventeenth century

The
average of these values found in Table 2 above compares with the value of
21.637mm found above. The difference is only 0.08% and therefore there is
strong agreement among the five different instruments. This therefore suggests strongly
that Guarracino was the maker of the RCM175 instrument. The results of the
calculation of the unit of measurement on all of these different instruments
shows that Guarracino must have had his own workshop unit which, although it was
clearly close to the ‘standard’ text-book unit used in Naples (=21.835mm), was significantly
different from it by an amount that would be distinguishable by straightforward
measurement. The discovery that Guarracino, although basically using the
Neapolitan unit, had his own individual workshop unit that was slightly
different from the ‘standard’ Neapolitan unit is one of most important factors
that can be used to attribute instruments to him. Any instrument with all of
the usual features of Guarracino’s work and which uses this unit of
measurement is therefore almost certainly by Guarracino and not by one of his
contemporaries working in Naples. The difference between the workshop unit used
by Guarracino and this ‘standard’ unit of measurement is therefore one of the
many indications that RCM175 is by Guarracino. It has many characteristics of
other Neapolitan keyboard instruments but is characterised by the use of the
workshop unit of measurement used only in other instruments by Guarracino. This
therefore helps to tie it down to this one specific maker.

The alteration
of these two instruments by Cristofori/Ferrini

Before starting this discussion it has to be made clear that it is much more
difficult to attribute the alteration of an instrument to a given maker than it
is to attribute an unaltered instrument by the same maker. The number of
clues to the authorship of an alteration are clearly far fewer than if the
instrument were built from scratch by a given builder. What, then, are some of
the characteristics of Cristofori and Ferrini that can be used to establish the
presence of their hand in the alteration of these two instruments:

1.The use of the Florentine soldo based on
the Florentine braccio divided into 20 units.

2.The use of construction characteristics typical
of the Cristofori/Ferrini workshop. The typical internal bracing system which
they used can obviously not be considered here because the case structure of
these instruments already existed. However, the Cristofori/Ferrini instruments
always have an extremely robust structure for hitching the bass strings and
supporting the higher bass string tension. Further, the jacks are guided, like
other instruments of the Florentine school such as those of de Quoco, using
upper and lower guides instead of the more ‘classic’ Italian boxslides.

3.The key guiding system sometimes found with
round wooden pegs between the tails of the keylevers instead of the more usual
wooden slip sliding in a rack is a characteristic not found in the instruments
of other builders.

4.The use of short sections of bridge placed
parallel to the main section of bridge in the bass, rather than the more common
mitred-section characteristic of almost all other makers.

Figure 3 - The bass ends of the 8'
bridge showing the 'added' section of bridge place parallel to the main bridge
on the right. A close look at the far ends of the bass strings shows they
only pass what appear to be hitchpins, and are not attached to them.
Instead the strings pass through the tail of the case and are attached to
hitchpins which are driven into uthe outside of the tail and into the bass liner
below the soundboard liner and soundboard. Notice how closely the bridge
pins are placed to the ends of the bridge sections.

5.The use of two angled almost vertical cuts at
the ends of the bridges and nuts, placed very close to their ends and to the
last bridge or nut pin. This results in a maximum area of freely-vibrating
soundboard near the ends of the bridge with a consequent improvement in the
sound of the instrument at the extreme ends of the compass.

6.The use of some of the mouldings also found on
other instruments by Cristofori and Ferrini.

7.The use of the double ovolo moulding on both
the front and back edges of the bridge and nut.

It
was the last of these characteristics that first drew my attention to the fact
that the two instruments just discussed might have been re-worked by Cristofori
or Ferrini. Although the bridges clearly belonged to the original states of
both instruments, the nuts were replacements and seemed clearly to have come
from the Cristofori/Ferrini workshop. Also the jacks in both of these two instruments are guided in upper and lower registers and not in boxslides, and
the mouldings on the outside edges of these registers are similar to those found
on other harpsichords by Cristofori and Ferrini. These are shown in Figure
4:

Nuts
and Bridges

Russell Collection
RCM175

Upper
Register Guides

Russell
Collection RCM175

Figure 4 - Some
Cristofori/Ferrini features

A comparison of the Russell
Collection and the RCM single-manual harpsichords

In
addition to the typical rounded mouldings along the front and back edges of the
nuts, both instruments have the characteristic almost vertical angled cuts at
the ends of both the bridges and the nuts. The Russell Collection harpsichord
also has an unusual system of attaching the bass strings. Instead of being
hitched to pins inside the case along the tail as is normal practice, Cristofori
or Ferrini has cut neat small square holes just above the tail hitchpin
moulding, and the bass strings pass through these holes and hitch to pins placed
in the outside of the case about 30mm below the holes. This extraordinary
system seems to be typical of a pre-occupation with attaching the bass strings
in a way which is completely secure and which will not result in a splitting of
the bass hitchpin moulding or tail liner. It is, to be sure, completely secure
and free of any tendency to splitting.

Although it does not have any ‘belt and braces’ method of attaching the bass
strings, the RCM harpsichord has the typical key-guiding system of Cristofori
and Ferrini with small wooden pegs placed between the tails of the keylevers and
the keyframe itself slides in and out of the instrument like a drawer. All of
these features, along with the typical upper and lower jack guides, seem to me
to indicate that either Cristofori or Ferrini had a hand in the re-working of
both of these instruments.

Figure
5 - The keyboard of the harpsichord RCM175 with keyboards by
Cristofori/Ferrini features showing the pegs used to guide the keylevers near
the keylever tails.

Single-manual harpsichord, attributed to Onofrio Guarracino, RCM175, in the
Royal College of Music, London

In
addition to this it seems clear that a number of features of these instruments
are based on the use of the Florentine soldo measurement. What I want to
show is that Cristofori and Ferrini used a soldo = 27.53mm which was a
twentieth part of the Florentine braccio = 550.64mm. In this connection
and before looking at the string scalings of the two instruments discussed above
I would like to have a look first at the scalings of an instrument made from the
start by Cristofori. Figure 5 below shows the string scalings of the
single-manual harpsichord by Bartolomeo Cristofori dated 1722 in the
Musikinstrumentenmuseum of the University of Leipzig. This shows that
Cristofori paid close attention to ensuring that the string scalings of his
instruments had Pythagorean scalings which doubled in length with each octave drop in pitch as far down in the compass
as was possible, and in this case right down to tenor c. It also shows that if
the length of the soldo given above is correct, then the scalings are
based on c2 = 101/3 soldi.

Figure 6 below shows the string scalings of RCM 175. Like the Russell Collection
harpsichord, the nut is a replacement and the compass has been changed, and
therefore the present position of the nut reflects a string scaling design
appropriate to the re-working of the instrument, rather than to that of its
original design. In this case it seems clear that this design was based on a
treble scaling of 9soldi, although in this case,
because the instrument originally had an enharmonic compass with more than 12
notes to the octave, it was possible to achieve
Pythagorean scalings for only a part of the compass in the treble.

Similarly Figure 7 shows the string scalings of the Russell Collection harpsichord which
seems to have scalings based on 9¾ soldi. This is close to a semitone
higher than RCM 175 and a semitone lower than the 1722 Leipzig harpsichord by
Cristofori. It therefore appears that Cristofori/Ferrini were working to at
least 3 different pitch levels differing from one another by semitone intervals.

Figure 7 -
String Scalings

Anonymous Italian single-manual
harpsichord, Naples, c.1620

Russell Collection, Edinburgh, Cat.
No. HS1-A1620.2

Figure 8 below shows a graph of the jackslot spacing of the front register of RCM
175. Here the distance from the spine of the instrument to the edge of
each jackslot is plotted against the note sounded by the jack whose jackslot is
being measured. The uniform spacing of the jackslots gives rise to a
straight line plot whose mathematical characteristics can be calculated using
the usual statistical analysis.

Figure 8 -
Spacing of the jackslots in units of both the Neapolitan oncia and the
Florentine soldo.

Using
the usual regression analysis by the method of least squares, calculation gives a
correlation coefficient for this data of r = 0.999993572 indicating a very good
fit of the measured data to a straight line. The calculated slope of the line
is m = 13.7675mm/jackslot.

This
slope = 13.7675mm/jackslot is equivalent to 0.50005soldi/jackslot, based
on the Florentine soldo of 27.532mm, or to a spacing of 0.63154
Neapolitan once or to 7/11 = 0.63636 Neapolitan once according to
the values found in the
reference tables. This
therefore appears to be a spacing of exactly 50 jackslots in 25 soldi:

Using the value of the Florentine soldo used by Cristofori to calculate the soldo gives:

1 soldo =
(13.767x50)/25 = 27.535mm.

This
compares with the value given by both Vega and Colonel Cotty[4]
for the braccio divided into 20 soldi of 550.64mm, or of 1 soldo
= 550.64/20 = 27.532mm. This only 0.01% different from that estimated
here and strongly suggests that the register slots were cut out by designing
them to be exactly ½ of a Florentine soldo apart.

Clearly because the spacings used by Guarracino in once are the
same, Cristofori simply used his unit to mark out the registers for the
up-dated, modernised instrument.

Although different from RCM 175 because of the existence of different space
constraints imposed by the re-working of instruments with different widths, the
jack spacing the Russell Collection harpsichord is also clearly based on the
Florentine soldo. In this case, however, there are 51 jackslots in 25
soldi giving rise to a calculated Florentine soldo of 27.328, again
only marginally different (error = 0.75%) from the value found in the tables.

It
would be an incredible coincidence if these two instruments, both of which have
numerous characteristics of the instruments of Cristofori and Ferrini, where not
altered by one or the other of these two Florentine builders. The use of the
Florentine soldo in the scaling design and in the design of the register
spacing of both instruments certainly makes clear that they were altered in
Florence. This, in addition to the many other characteristics individual
to Cristofori and Ferrini, make it almost a
certainly that one of these two had a hand in the re-working of these
instruments.

I
conclude by posing three questions:

Why are there no early Florentine signed or
anonymous instruments which have been re-worked by Ferrini or Cristofori both of
whom worked in Florence where one would have expected numerous out-of-date
instruments of Florentine origin?

Following on from this, did Cristofori and
Ferrini engage in a commercial trade in old, out of date instruments which they
bought in the south of Italy and then re-worked to sell on again? Were the
harpsichords made in Naples therefore especially valued by Cristofori and
Ferrini to the extent that they engaged in such a trade to the exclusion of
locally made harpsichords?

What are the characteristics that distinguish
Cristofori’s work from that of Ferrini, and therefore how can we distinguish the
work of these two important Florentine master/apprentice harpsichord makers? One distinguishing
feature seems to be the use of round pegs to guide the key tails as a practice
characteristic only of Ferrini’s work. Are there any others?

[1] In the North-European
tradition where the case sides are much thicker than in Italian practice,
the moulding is often cut into the top of the case side itself, and the case
sides are usually (but not always) applied to the top of the baseboard. It
is therefore the case height less the thickness of the baseboard that the
maker would measure out in a simple number of local units.

[2] Denzil Wraight, in his
otherwise splendid work on the identification of Italian keyboard
instruments, rejects the evidence provided by the local unit of measurement
(see:Denzil Wraight, ‘The identification and authentication
of Italian string keyboard instruments’, The Historical Harpsichord.
Volume Three, general editor Howard Schott, (Pendragon Press,
Stuyvesant, NY, 1992) pp. 66-76). Unfortunately he seems to reject the
whole process of using the local unit of measurement as a method for
determining the origin of an instrument on the basis of a quoted example of
the confusion that has arisen because of the fact that the Frankfurt and
Vicenza inches are fortuitously in the ratio of 3 to 4.